1. Field of the Invention
The present invention relates to a multiantenna unit and a communication apparatus, and more particularly, it relates to a multiantenna unit and a communication apparatus each including a plurality of antenna elements.
2. Description of the Background Art
A multiantenna unit including a plurality of antenna elements is known in general, as disclosed in Japanese Patent Laying-Open No. 2007-97167, for example.
The aforementioned Japanese Patent Laying-Open No. 2007-97167 discloses an MIMO array antenna (multiantenna unit) including a first antenna element, a second antenna element and an isolation element (passive element) arranged between the first and second antenna elements. The isolation element has an electrical length of substantially one wavelength, and is partially grounded to a ground plane.
In the MIMO array antenna according to the aforementioned Japanese Patent Laying-Open No. 2007-97167, however, intercoupling between the first and second antenna elements can be suppressed due to the provision of the isolation element (passive element), while the isolation element must be grounded to the ground plane and hence flexibility in wiring pattern design is disadvantageously reduced. In general, a multiantenna unit is loaded on a portable apparatus, and hence further downsizing of the multiantenna unit is required.